a sewing machine

Abstract

The invention belongs to the technical field of sewing devices, and particularly discloses a sewing machine. The sewing machine comprises a stitch-length adjusting screw column, an adjuster shaft, a stitch-length adjuster fixed on the adjuster shaft and a swinging base swinging on a bottom plate through a first positioning pin and a second positioning pin, the upper end of a back feeding connecting rod is connected on the stitch-length adjuster, the lower end of the back feeding connecting rod is connected on the swinging base, and the swinging base is also connected with the lower end of a backstitch pulling rod; both the backstitch pulling rod and the back feeding connecting rod are connected at the same end of the swinging base, the upper end of the backstitch pulling rod is hinged to an iron core of a backstitch electromagnet through a backstitch crank, the backstitch crank is fixedly arranged on a backstitch wrench shaft, the backstitch wrench shaft is driven by the backstitch electromagnet to rotate, and the middle of the back feeding connecting rod is connected with the bottom plate through a reset pulling spring. According to the sewing machine, a transmission chain of a front-stitch and backstitch mechanism is simplified, complex part designing is simplified, and the processing cost of parts is reduced.

Description

Technical field: [0001] The invention belongs to the technical field of sewing equipment, in particular to a sewing machine. Background technique: [0002] When the lockstitch sewing machine is sewing, the reverse stitching is often used to reinforce the sewing material at the beginning and end of the stitching. In order to make the stitches beautiful, it is required that the forward and reverse stitches have the same pitch so that the stitches can overlap perfectly. [0003] The existing sewing machine stitch distance switching structure is as follows: it includes a stitch length adjustment stud, an adjuster shaft and a stitch length adjuster fixed on the adjuster shaft. The stitch length adjuster includes a main body, and at one end of the main body A V-shaped groove is provided, and a crank part connected to the upper end of the reverse feeding connecting rod is provided at the other end of the main body. A fork is provided at the lower end of the main body between the V-...

AI Technical Summary

Problems solved by technology

[0004] It can be seen from the above that the structure of the stitch length adjuster and the reverse stitching crank in the existing structure is complicated, the processing cost is high, and the transmission chain of the overall structure is redundant and the structure is complicated

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